I'm talking about my baby sitter, of course. We found each other online, in the trusty land of profile pictures and background checks. This is how needs are met — relational or otherwise — in a post-fate era. Very little is left to chance. Algorithms are the new serendipity.

So back when I needed a sitter to hang with my son during the day and pick up my daughter from school, I posted an ad filled with words like "fun-loving" and "charming" and "$14/hour" and waited for the suitors to pour in.

Pour in they did. The pescetarian dietetics student with exacting housekeeping standards! The loving, bilingual mom of two grown kids! The elementary education student with her own car! All of them willing to take a chance on me!

It was exhilarating.

In the end, Maria, the banjo-playing improv actor, won my heart. She struck me as someone my kids would enjoy seeing each morning, which is more important than housekeeping.

She turned out to be as lovely as I imagined and she brightened our world in ways that are difficult to quantify, but a joy to contemplate.

I patted myself on the back more than once for making such an inspired pick amid the complicated equations and endless choices. All those stories from my single pals about miserable dates, misread cues and unreturned texts? I didn't get it.

"What's so hard?" I thought. "Just go with your gut. After, obviously, Googling each person into the wee hours of the morning and cross-checking the results against Facebook. You know, like our grandparents did."

This round is not going as well. My husband and I need a sitter on occasion. I dusted off my charming profile and made coffee dates with the applicants.

There was the delightful 20-something who my kids and I interviewed at Starbucks. We were fun-loving and witty and dazzled her with our interests. ("Power Rangers, Uno, crafts that involve glitter, karaoke.") I could tell she loved us.

I emailed her: "Thanks for meeting!" She ignored me. I emailed her for references. She ignored me. Two weeks later, she emailed to say she could baby-sit on an upcoming Friday. An hour later, she emailed to cancel.

No excuse is too small for my new would-be matches to bail. Foul weather, sick dog, lost keys.

This is torture. Ego-crushing, mind-numbing torture. I turned to my colleague Alexia Elejalde-Ruiz, a gorgeous, wise, online-dating veteran, for guidance.

"What's up with having a first 'date' go swimmingly," I asked, "only to never hear from the person again?"

"More infuriating," she replied, "is having four dates go swimmingly, only to never hear from the person again. But ultimately it's OK because there's usually someone a little greater around the corner."

"So do you find yourself thinking, 'This person's great! But what if someone's a little greater?'" I wondered.

"Every time."

"But don't you worry, other people are thinking the same thing about you?"

"Those people are deluding themselves," she said. "Just kidding. If they find someone greater, they should have her."

There's a chance I'm not cut out for this era. Somehow fate not working out in your favor is easier to swallow than consulting a vast network of mathematically sound matches and coming up short.

I asked Alexia, "Does putting your needs out there, only to have them repeatedly not met, get less soul-crushing over time?"

"Absolutely," she assured me. "Crushed little souls have thick skins. On occasion, however, it gets more soul-crushing, and you find yourself anticipating disappointments before the person has a chance to let you down, which apparently isn't so attractive."